1004 on Rows("1:10").Select

I get run-time error 1004, on this very simple code:

Sheets("Beosztasok").Activate
    ActiveCell.Offset(1, 0).Select
    Rows("1:10").Select 'Here comes the error message.

Tried lots, none works. Have no clue this time, what it might be. xl2016.

With Sheets("Beosztasok")
    .Activate
    .Rows("1:10").Select
End With

It works for me although I don't see why this line of code is necessary:

ActiveCell.Offset(1, 0).Select

It doesn't seem to serve any purpose.

sorry, I got it wrong: the code was on a worksheet module.
As soon as I moved over to a module it started working...